Delivery system, method, and anchor for medical implant placement

Abstract

A delivery system and method for placing a medical implant, such as for diagnosing, monitoring and/or treating cardiovascular diseases. The delivery system includes a hollow catheter, an anchor coupled to the catheter, and an implant secured within the anchor. The anchor has a base portion with first and second longitudinal ends and a cage therebetween. The anchor further has flexible arms, flexible legs, features for securing the medical implant within the cage of the base portion, and a coupler portion connected to and spaced apart from the second longitudinal end of the base portion. Surfaces of the arms and legs are adapted to clamp the anchor to a wall. The system further includes a pusher wire adapted to cause the anchor to acquire a stowed configuration in which the legs axially extend from the base portion, permitting the anchor to be retrieved after its deployment.

The invention claimed is: 
     
       1. A delivery system comprising a hollow catheter, an anchor coupled to the catheter, and an implant secured within the anchor, the anchor having stowed and deployed configurations and comprising:
 a base portion having a longitudinal axis and comprising first and second longitudinal ends in oppositely-disposed first and second longitudinal directions, respectively, of the anchor, and a cage between the first and second longitudinal ends; 
 a coupler portion releasably coupled to the catheter and connected to and spaced apart from the second longitudinal end of the base portion in the second longitudinal direction of the anchor; 
 a plurality of flexible arms that, in the stowed configuration of the anchor, axially extend in a distal direction from the first longitudinal end of the base portion and being resiliently biased so that, in the deployed configuration of the anchor, the arms radially project away from the first longitudinal end of the base portion and axially project toward the second longitudinal end of the base portion, each arm having a span portion terminating in a distal portion of the arm, the distal portion having a semispherical shape that defines a convex surface facing the second longitudinal direction; and 
 a plurality of flexible legs connected to the coupler portion and to the second longitudinal end of the base portion, each leg axially extending in a proximal direction from the second longitudinal end of the base portion in the stowed configuration of the anchor and being resiliently biased to project radially away from the longitudinal axis of the base portion and axially project toward the first longitudinal end of the base portion in the deployed configuration of the anchor, each leg having a first span portion adjoining the second longitudinal end of the base portion, a second span portion adjoining the coupler portion, and an intermediate portion therebetween, the intermediate portion having a semispherical shape that defines a convex surface facing the first longitudinal direction; 
 wherein the medical implant is secured within the cage of the base portion so that at least a portion of the implant is between the first and second longitudinal ends of the base portion; and 
 wherein the delivery system further comprises a pusher wire received in the catheter and adapted to apply a force to the implant in the distal direction so as to cause the legs to move from the deployed configuration, whereby the legs project radially away from the longitudinal axis of the base portion and axially project toward the first longitudinal end of the base portion, to the stowed configuration, whereby the legs axially extend in the proximal direction from the second longitudinal end of the base portion. 
 
     
     
       2. The delivery system according to  claim 1 , further comprising means for articulating movement of the anchor relative to the catheter in directions transverse to the longitudinal axis of the base portion. 
     
     
       3. The delivery system according to  claim 2 , wherein the articulating means comprises longitudinal slots defined in the coupler portion, each of the longitudinal slots having a recess therein and being contiguous with an end of the coupler portion farthest from the base portion, and the catheter comprises connectors received in the longitudinal slots and engaging the recesses in the longitudinal slots. 
     
     
       4. The delivery system according to  claim 3 , wherein the connectors of the catheter are operable to decouple from the coupler portion by moving in radially outward directions from the coupler portion to disengage the recesses of the longitudinal slots. 
     
     
       5. The delivery system according to  claim 3 , wherein the articulating means further comprises means for causing differential movement of the connectors to cause articulation of the anchor relative to the catheter. 
     
     
       6. The delivery system according to  claim 1 , further comprising a sheath in which the catheter is telescopically received. 
     
     
       7. The delivery system according to  claim 6 , wherein the anchor is stowed within the sheath and the arms and the legs of the anchor are elastically deformed to acquire the stowed configuration of the anchor in which the arms extend parallel to the longitudinal axis of the base portion from the first longitudinal end of the base portion and the legs extend parallel to the longitudinal axis of the base portion between the coupler portion and the second longitudinal end of the base portion. 
     
     
       8. The delivery system according to  claim 7 , wherein in the stowed configuration the convex surfaces of the distal portions of the arms face radially outward from the longitudinal axis of the base portion and the distal portions of the arms project radially inward over an end surface of the medical implant. 
     
     
       9. The delivery system according to  claim 1 , wherein the pusher wire has a distal end adjacent the anchor, the delivery system further comprises a handle attached to a proximal end of the pusher wire, and the pusher wire has a length between the distal end thereof and the handle thereof that precludes the implant from being dislodged from the anchor when the force is applied by the pusher wire to the implant in the distal direction. 
     
     
       10. A method of delivering and implanting a medical implant with the delivery system of  claim 1 , the method comprising the steps of:
 placing the catheter within a sheath so that the arms and the legs of the anchor are elastically deformed to acquire the stowed configuration of the anchor in which the arms extend parallel to the longitudinal axis of the base portion from the first longitudinal end of the base portion, the convex surfaces of the distal portions of the arms face radially outward from the longitudinal axis of the base portion, the distal portions of the arms project radially inward over an end surface of the medical implant, and the legs extend parallel to the longitudinal axis of the base portion between the coupler portion and the second longitudinal end of the base portion; 
 placing a longitudinal end of the sheath through an internal wall of a human body; 
 with the anchor positioned within the longitudinal end of the sheath, moving the catheter in the first longitudinal direction of the anchor to deploy the arms so that the convex surfaces of the arms engage a distal surface of the internal wall; and 
 securing the anchor and the medical implant within the cage of the anchor to the internal wall by moving the sheath in the second longitudinal direction of the anchor to deploy the legs so that the convex surfaces of the legs engage a proximal surface of the internal wall, wherein the internal wall is clamped between the convex surfaces of the arms and legs of the anchor. 
 
     
     
       11. The method according to  claim 10 , further comprising retrieving the implant by pulling the anchor in the proximal direction with the catheter into the sheath while pushing on the implant in the distal direction with the push wire to cause the legs to reacquire the stowed configuration thereof. 
     
     
       12. The method according to  claim 11 , further comprising directly repositioning the implant without extracting the implant from the human body. 
     
     
       13. The method according to  claim 11 , wherein the anchor is coupled to the catheter by connectors of the catheter that are received in longitudinal slots in the coupler portion and engage recesses of the longitudinal slots. 
     
     
       14. The method according to  claim 13 , further comprising articulating the anchor relative to the catheter by causing differential movement of the connectors. 
     
     
       15. The method according to  claim 13 , further comprising decoupling the anchor from the catheter by causing the connectors of the catheter to move in radially outward directions from the coupler portion to disengage the recesses of the longitudinal slots. 
     
     
       16. The method according to  claim 15 , further comprising recoupling the catheter with the anchor by causing the connectors of the catheter to move in radially inward directions toward the coupler portion to re-engage the recesses of the longitudinal slots. 
     
     
       17. The method according to  claim 16 , wherein the recoupling step is performed after the catheter and the sheath have been removed from the human body. 
     
     
       18. The method according to  claim 11 , wherein the securing of the anchor and the medical implant to the internal wall placement is part of at least one procedure chosen from the group consisting of diagnosing a disease of an internal organ, monitoring a disease of an internal organ, and treating a disease of an internal organ. 
     
     
       19. The method according to  claim 18 , further comprising wirelessly communicating with the medical implant using a reader unit external to the human body. 
     
     
       20. The method according to  claim 19 , wherein the medical implant is a cardiovascular implant and the internal wall is a portion of a cardiovascular organ. 
     
     
       21. The method according to  claim 19 , wherein the internal organ is a heart and the internal wall is a septum of the heart. 
     
     
       22. The method according to  claim 11 , wherein the procedure is chosen from the group consisting of diagnosing a cardiovascular disease, monitoring a cardiovascular disease, and treating a cardiovascular disease. 
     
     
       23. The method according to  claim 22 , further comprising wirelessly communicating with the medical implant using a reader unit external to the human body. 
     
     
       24. The method according to  claim 23 , wherein the cardiovascular disease is congestive heart failure, valvular heart disease, systemic pulmonary hypertension, or congenital heart disease.